Thermal management of nano-encapsulated PCM nanofluids in a square enclosure featuring dual-heated cylinders

Purpose This study investigates the thermal management of a cold square enclosure featuring dual-heated circular cylinders. These cylinders are arranged in various orientations from horizontal to vertical around a central point within the enclosure. The purpose of this paper is to explore the mechanisms of flow patterns, phase change structures and total thermal efficiency of the system. Design/methodology/approach The governing equations for the phase change material (PCM) suspension have been transformed in a dimensionless system and solved numerically with a finite element method. A penalty parameter is used to eliminate pressure-related difficulties. Findings The findings reveal that the vertical array of cylinders provides the maximum heat transfer augmentation. Increasing the volume fraction of nano-encapsulated phase change material (NEPCM) by 2% leads to substantial 65% rise in the average Nusselt number at S = 0.6 and Ra = 104. Research limitations/implications This research is limited to the steady-state and two-dimensional laminar flow. Practical implications NEPCMs enhance thermal energy storage by combining the high latent heat capacity of PCMs with the improved conductivity of nanoparticles. This combination results in more efficient heat transfer and better thermal management in engineering applications. Originality/value This study addresses the identified gap by investigating free convection in a cold enclosure containing two heated cylinders immersed in NEPCM nanofluids, with varying spacing and angular orientations. Unlike prior studies that primarily focused on conventional fluids or single-cylinder configurations, this research uniquely explores how NEPCM nanofluids influence convective heat transfer and flow behavior in dual-cylinder arrangements.